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Posted to issues@hbase.apache.org by "Yu Li (JIRA)" <ji...@apache.org> on 2016/01/19 16:04:39 UTC
[jira] [Commented] (HBASE-13960) HConnection stuck with
UnknownHostException
[ https://issues.apache.org/jira/browse/HBASE-13960?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15106845#comment-15106845 ]
Yu Li commented on HBASE-13960:
-------------------------------
We encountered the same issue months ago in our 0.98.12 cluster, and fixed it with a similar solution. When trying to contribute our work back along with our upgrading to 1.x, found this one by searching.
The patch here is a little stale that cannot compile with latest code base. After some minor change, it works and the UT design is good enough to produce the issue. UT could pass w/ patch (main changes on AbstractRpcClient), and fail with below exceptions w/o patch:
If UnknownHostException thrown during locate region in meta
{noformat}
2016-01-19 22:07:14,712 DEBUG [Time-limited test] client.ConnectionImplementation(944): locateRegionInMeta parentTable=hbase:meta, metaLocation=, attempt=0 of 36 failed; retrying after sleep of 100 because: Failed after attempts=36, exceptions:
Tue Jan 19 22:07:14 CST 2016, null, java.net.SocketTimeoutException: callTimeout=60000, callDuration=68243: row 'testRegionServerRandomRpcFail,row,99999999999999' on table 'hbase:meta' at region=hbase:meta,,1.1588230740, hostname=localhost,55113,1453212381028, seqNum=0
{noformat}
If thrown during puts:
{noformat}
2016-01-19 22:04:25,685 INFO [hconnection-0x3eeadfbb-shared-pool14-t1] client.AsyncProcess$AsyncRequestFutureImpl(1222): #12, table=testRegionServerRandomRpcFail, attempt=24/36 failed=1ops, last exception: java.net.UnknownHostException: unknown host: random_invalid_host on localhost,54943,1453211970421, tracking started null, retrying after=20005ms, replay=1ops
2016-01-19 22:04:25,695 INFO [main] client.AsyncProcess(1711): #12, waiting for some tasks to finish. Expected max=0, tasksInProgress=24
2016-01-19 22:04:45,698 INFO [hconnection-0x3eeadfbb-shared-pool14-t1] client.AsyncProcess$AsyncRequestFutureImpl(1222): #12, table=testRegionServerRandomRpcFail, attempt=25/36 failed=1ops, last exception: java.net.UnknownHostException: unknown host: random_invalid_host on localhost,54943,1453211970421, tracking started null, retrying after=20176ms, replay=1ops
2016-01-19 22:04:45,698 INFO [main] client.AsyncProcess(1711): #12, waiting for some tasks to finish. Expected max=0, tasksInProgress=25
{noformat}
Will upload the updated patch soon.
> HConnection stuck with UnknownHostException
> --------------------------------------------
>
> Key: HBASE-13960
> URL: https://issues.apache.org/jira/browse/HBASE-13960
> Project: HBase
> Issue Type: Bug
> Components: hbase
> Affects Versions: 0.98.8
> Reporter: Kurt Young
> Attachments: HBASE-13960-0.98-v1.patch, HBASE-13960-v2.patch
>
>
> when put/get from hbase, if we meet a temporary dns failure causes resolve RS's host, the error will never recovered. put/get will failed with UnknownHostException forever.
> I checked the code, and the reason maybe:
> 1. when RegionServerCallable or MultiServerCallable prepare(), it gets a ClientService.BlockingInterface stub from Hconnection
> 2. In HConnectionImplementation::getClient, it caches the stub with a BlockingRpcChannelImplementation
> 3. In BlockingRpcChannelImplementation(),
> this.isa = new InetSocketAddress(sn.getHostname(), sn.getPort()); If we meet a temporary dns failure then the "address" in isa will be null.
> 4. then we launch the real rpc call, the following stack is:
> Caused by: java.net.UnknownHostException: unknown host: xxx.host2
> at org.apache.hadoop.hbase.ipc.RpcClient$Connection.<init>(RpcClient.java:385)
> at org.apache.hadoop.hbase.ipc.RpcClient.createConnection(RpcClient.java:351)
> at org.apache.hadoop.hbase.ipc.RpcClient.getConnection(RpcClient.java:1523)
> at org.apache.hadoop.hbase.ipc.RpcClient.call(RpcClient.java:1435)
> at org.apache.hadoop.hbase.ipc.RpcClient.callBlockingMethod(RpcClient.java:1654)
> at org.apache.hadoop.hbase.ipc.RpcClient$BlockingRpcChannelImplementation.callBlockingMethod(RpcClient.java:1712)
> Besides, i noticed there is a protection in RpcClient:
> if (remoteId.getAddress().isUnresolved()) {
> throw new UnknownHostException("unknown host: " + remoteId.getAddress().getHostName());
> }
> shouldn't we do something when this situation occurred?
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